|Positive Mitzvah Sixty-Nine
The Fixed Chataat [sin]-offering
Requires Beit HaMikdash
We are commanded that whenever an individual has sinned unintentionally he must offer a Chataat-offering.
Sins which when committed incur the penalty of a Chataat-offering are those for which the penalty is extinction when they are committed willfully, provided that the sin involves violation of a Negative Mitzvah, and that there is some act connected with it. Thus, the Pesach-offering and Circumcision, being Postive Mitzvot, and entailing extinction if willfully transgressed do not involve a fixed Chataat-offering if transgressed unintentionally. Blaspheming the Name, invoivling mere utterance and connected with no act, entails extinction if willfully committed, but does not entail a fixed Chataat-offering if committed unintentionally.
In the Mishneh Torah RaMBaM enumerates forty-three sins which if committed unintentionally entail a fixed Chataat-offering (Mishneh Torah, Korbanot, Hilchot Shegagot 1, 4)
Repentance was also the essential prerequisite for the atonement of all Yisrael on Yom Kippur (see Positive Mitzvah 49)